Screw-machine



A. JOHNSTON. SGREW MACHINE..

No. 316,788. Patented Apr. z8, m5.

(No Model.) 4 Sheets-Shelst l..

U H11` MVIUIIWIHHIA (No Model.) 4 Sheets-Sheet 2.

A. JOHNSTON'.

SCREW MACHINE.

No. 316,788. Patented Apr. 28, 1885.

N w' Ln' LT. I

M@ LymaJw/V, nvenr s (No Model.)v A' JOHNSTON. 4Sheets--Sheet 3.

SGREW MACHINE.

No. 316,788. -Panentedvilprl 28, 1885.

(No Model.) A' 4Sheets-Sheet 4.

SCREW MACHINE. No. 316,788. Patented Apr. 28, 1885.

FIG.10-

Y veul-1071] N. PETERS PhmLimugnpher. wam; nnnnnn a ALLEET JOHNSTONA OF OTTUMVA, IOW'A.

'SCREW-MACHINE.

SPECIFICATION forming part of Letters Patent No. 316,788, dated April 28, 1885.

Application Iiled October 23, 1884. (No model.) i

To all whom it may concern:

Be it known that I, ALLEN JoHNsroN, of Ottumwa, in the county of Wapello and State of Iowa, have invented a new and useful Improvementin Screw-Machines, which improvement is fully set forth in the following specification.

This invention relates to machinery for making screws (male and female) and other articles from a long rod or stock by shaping the end of the same, and when necessary screwthreading it, and then cutting off the shaped or shaped and threaded end. Parts of the invention may, however, be useful in machinery for other purposes.

The invention consists, iirst, in a new arrangement for or mode of bringing the tools successively into action. As common in metal screw-machines, the stock is held in a chuck, and the tools are held in a turret mounted on a slide that moves longitudinally otl the machine or parallel to the axis of the chuck; but the said turret, instead of being mounted on an upright axis or axis perpendicular to the plane of the slides movement, as heretofore, is mounted on an axis parallel to said plane and to the chucks axis. The tools are thus always parallel to or in line with the chucks axis, and are not so liable to get out of true as `with the ordinary turret. There are also other Aadvantages of a practical nature, which will be readily understood by those skilled in the art.

The invention, secondly, consists in a new arrangement for or mode of revolving the threading-tool in the turret. Heretofore in many machines the die or threading-tool has been revolved sometimes in cutting the thread, (see my Patent No. 241,806, dated May 24, 1881,) and sometimes in unthreading or backing oft' the die or top. (See my Patent No. 211,742, dated January 28, 1879.) Heretofore, when the threadingtool has been held in a turret, motion has been communicated to the spindle ofthe threadingtool from a gear or its equivalent outside the turret. In the present improvement' a shaft enters the turret axially, and motion is communicated to the tool-spindle through a gear on the end of the said shaft.

The invention, thirdly, consists in mechan ism for closing the chuck-jaws by a positive movement. In order to accommodate the small irregularities in the stock or rod held by the jaws a spring is interposed between the parts of the actuating mechanism. Here` tot'ore the jaws have been closed by a spring, which is retracted for opening the jaws.

The invention, tourthly, consists in an arrangement of screws and wedges for closing the jaws with a very powerful pressure.

The invention also comprises certain particular constructions, combinations, and arrangements of parts, as hereinafter more fully set forth.

The accompanying drawings represent a metal screw-machine constructed in accordance with the invention.

Figure 1 is a central vertical longitudinal section ofthe machine; Fig. 2, a sectional elevation of the chuck-spindle and contained parts; Fig. 3, a front view of the chuck; Fig. 4, a side view of one part of the chuck; Fig. 5, a cross-section on line u u, Fig. 2; Fig. 6, a plan of the machine with the upper part removed; Fig. 7, a development on a plane of the cani-drum for bringing the tools into and out of action; Fig. 8,'a vertical cross'section on line a: x of Fig. l, and in elevation, looking tothe left; Fig. 9, an end elevation; Fig. 10, avertical crosssection on line y y, Fig. 1, and Fig. 11, a similar sect-ion on line .e e.

A is the machine-frame; B, a cam-shaft, and C the chuckspindle. The chuck-spindle is driven by abelt on pulley C. Motion is con` veyed from the gear b on the chuck-spindle to the camshaft through the gears b lf2, loose on the shaft b9, gears b3 6*, looseon shaft B, gear b5, supported in an arc-limb, gears b D7, Xed on shaft b9, and gear bs, fixed on shaft B, or by other suitable gearing or mechanical connection.

The chuck is constructed as follows: In the head c', at the inner end of the chuck-spindle, are secured wedges c2 for forcing in the chuck. These wedges, although they might be made separate, are united to form a ring. llihis wedge-ring is held from endwise movement by the flange c3 and the cap ct, which tits over the flange. A removable-locking-pin, c5, thatiits in one of the notches in the iiange ci, prevents it from turning. Inside the wedges or wedge- IOO.

ring o2 are the chuck-jaws c, formed in one piece of spring metal. These are beveled on the outside at the end to correspond with the bevel of the wedges. Behind the chuck-jaws is the follower a, connected with the wedge-ring o2 by the screw-th read 2, and with the tube ci by pins c7, tapped into said tube and workingin the oblique slots 3 in the follower. By turning the followerin the proper direction (which is effected by pushing in the tube c6) the screwthread 2 draws the follower forward, and it vin turn pushes forward the chuck-jaws c. As the latter advance, they are'forced together by the action of the wedges or wedge-ring c2, so as to grasp with great power the rod, blank, or stock inserted between them. When the tube o6 is drawn out, the'follower is turned in the opposite direction and withdrawn,`thereby releasing the chuck-jaws, which immediately expand and release the bite upon the rod, blank, or screw-stock. The tube c6 is moved in and out by the feed or chuck cam E, and is prevented from turning independently of the chuck-spindle by the splines s.

The device a, through which the motion is conveyed, has a pin, 4, that enters the groove 5 of the cam E, and an arm, 6, whose upper end projects between the nuts ca3 on the tube c6. A spring, F, is interposed between the arm 6 and the nut a3. It is shown as a strong spiral compressionspring. Its effect is to compensate for any inequalities in the size of 'the rod, blank, or screw stock. The device a', as shown, slides on the stud awhich is screwed into the machine-frame.

The groove 5 could extend all the way around the cam E; but practically vthis is not required, as when the chuck-jaws are conlpressed the friction (owing to the small pitch of thread 2) is sufficient to prevent their expanding.

The chuck can be adjusted at both ends ofthe chuck-spindle. For adjusting at theinner en d it is only necessary to remove the locking-pin v o5 and turn the wedgering cI in the proper direction. The screw-thread 2 then moves the follower back or forward (as the case may be) and compresses the chuck-jaws or allows them to expand a corresponding distance. rIhe locking-pin is then replaced. For adjusting at the outer end the nuts a2 a3 are screwed more or less on or -oft' the tube c.

The tool-holding turret G is mounted on the longitudinal slide H on an axis parallel with that of the chuck. It is inclosed in the head a on the slide,which constitutes at once a bearing and a cover or housing. Ajournal or stud, g,projecting rearward,carries a gear, g,which engages the gear or toothed wheel I,provided on the back face with projecting pins i for shifting the turret step by step.' The stud or journal g passes through the standard h on the slide H. The shifting-wheel I turns on a stud, h2, screwed into said standard. The shiftingwheel could,l of course, be fixed upon the journal g, the gear g being omitted. Under the ovm-hanging ern h3 of the slide H is a ,slide K. While the longitudinal slide remains back the cross-slide is moved (to the left,as shown in Fig. 8) so asto turn the wheel I, gear y', and turret G the proper distance to bring thenext tool in line with the chuck. A slot, 7c', is made in the cross-slide, and as the wheel I turns one of the pins' enters the slot. When the longitudinal slide is moved forward, the pins 't' are drawn out of the notch Ic and slot la in the cross-slide, and the latter sreturned to its original position. (Shown in Fig. 6.) The cross-slide K is reciprocated by the bent lever Ii', pivoted at k2 Ito the machine-frame, connected with the slide K l at 7c3 by a slot and pin, and operated by the cam-drum L, a pin, k, on the lever projecting into the irregular groove l on the periphery of the drum. The turret is prevented from turning when the longitudinal slide is moved forward to bring the tools into action by the device mit, fixed to the machine-frame and constituting a projection, which enters one o f the'notches 7 on the locking-plate Q, screwed or otherwise fastened to the turret.`

The tools are held in the ordinary or any suitable way in the turret. As shown, the turret is provided with four tool-holes, one containing the threading-tool, another being for a length-gage, and the two others forshaping-tools-such as a box tool, drill, turningdown tool, and the like.

The threading-tool consists of a cylindrical shell, M, a cap, m, a non-rotating elntchpiece, m', the' rotating clutch-piece m2, the gear m3, fast on the clutch-piece m2, the spin dle m, the clutch-piece `m5, fast on the spin.- dle, and the thread-cutter m. (Shown as aldie, but it could bea tap as well.) Motion is communicated from the gear n onthe chuckspindle through the gear n the shaft nz, (which extends axially into the turret,) the gear n3, and gear m3 to the clutch-piece?. Vhile the die or thread-cutter is in action,th e clutchpiece m5 is engaged by the clutch-piece m2, and the die or thread cutter is rotated in the same direction as the chuck, but at a greater speed. After the thread has been cut the die m, spindle m4,- and clutch-piece m5 are held from endwise movement, while the slide II, and with it the clutch-pieces m2 and m', is drawn back. The clutch-piecem5 is thus d isengaged from the rotating clutch-piece and engages the non-rotating clutch-piece m', whereupon the die or cutter m, being held stationary, the continued rotation of the chuck releases it from the newly-cut thread. The clutch-piece m is prevented from rotating by the screw m8, whose head fits in the slot m in IOO elenca the case M. A spiral compression-spring, mm,

is interposed between clutch-piece m and cap m.

`The cutting-oil` tool N -is mounted on a cross-slide,a, movable in ways of the machineframe, and is operated through the bentlever l), pivoted to the machine-frame, connected at y one end with the cross-slide n, and provided at the other end with a pin that projects into the groove ZZ in the periphery of cam-drum L. The weight W' for advancing the rod or stock is supported in the bightv of cord w, one end of which is held by the supporting-bar wl, and the other is connected with a slide or pusher-back of the rod or screw stock. The arrangement shown is the same as in 4my Patent No. 293,176, February 5, 1884.

llhe operation of the machine will be readily understood. The rod or screw-stock is introduced through the chuck-spindle and between the chuck-jaws, as usual. Suppose that a screw, a nut, or other article has just been severed from the rod or screw-stock and that the cutting-od' tool has been withdrawn. At this point the length-gage has been brought opposite the chuck and the longitudinal slide and turret have been moved forward, so that lthe pins i of the shifting-wheel I are clear of the cross-slide K. So soon as the cutting-off tool is out of the way, the cam E draws back the tube c6 and releases the chuck-j aws c, whereupon the weight W urges forward the rod or screw-stock until it strikes the length-gage. The cam E then advances the tube c, turning the follower a, and causing the chuck-jaws to resume their hold upon the rod or screw-stock. During this time the cross-slide K has been returned to the position shown in Fig. 9. Then the chuck has resumed its hold upon the rod or stock, the longitudinal slide is drawn back, the cross-slide is moved to turn the turret so as to bring one of the shapingtools into position, and the longitudinal slide is then advanced. Vhen the slide is moved forward, the cross-slide Kis returned. After the shaping-tool has cut as far as desired the longitudinal slide is returned, the cross-slide is shifted, turning the turret and bringing the next tool in line with the chuck. The longitudinal slide is now again advanced, the crossslide is returned, the longitudinal slide is drawn back, and the cross-slide is shifted, bringing the threading-tool in line with the chuck. The longitudinal slide is then advanced and returned, the cross-slide being returned while the turret is forward. During the thread-cutting the cutting-off tool is brought into action; but it does not completely sever the rod until the thread-cutter has been released from the newly-cut thread. During the last of the cutting-off tools action and the return of the said tool the turret is turned to bring the length-gage into line with the chuck, and the longitudinal slide is advanced the proper distance to bring the length-gage into y position to measure the rod when fed forward.

The machine herein described is more particularly designed to make thumb-nuts and long screws and such articles as cannot readily be made with the machine described in my Patent No. 299,477, dated May 27, 1884..

It is evident that modifications can be made in` details without departing from the spirit of the invention, and that parts of the invention may be used separately. For example, the tube in my Letters Patent of 1881 and 188.4, before referred to, which is arranged inside the chuck-spindle and is moved endwise to release and restore the bite of the chuck-jaws, could be operated by the mechanism herein described for operating the tube c6; also, the tube cherein could be operated as is the tube in the saidpatents. f

Having now fully described my said invention and-the manner of carrying the same into effect, what l claim is Y l. The combination, with the chuck, ofthe longitudinal slide and the `tool-holding turret mounted on an axis parallel with that of the chuck, and the automatic mechanism for revolving said turret to bring the tools successively in line with the said chuck, substantially as described.

2. The combination, with a turret and a threading-tool carried by said turret, of the axial. gear and the mechanism operated thereby for revolving the said threading-tool, substantially as described.

3. The combination ofthe chuck, the longitudinal slide, the tool-holding turret mounted on an axis parallel with that of the chuck, the threading-tool, and the gears for revolving said tool, substantially as described.

4. The combination, with the longitudinal slide and the tool-holding turret mounted on a horizontal axis on said slide, of the lockingplate and projection for holding the turret stationary when the slide is moved forward to bring the tools into action, substantially as described.

5. The combination, with the longitudinal slide and the toolholding turret mounted thereon, of they cross-slide and the shifting wheel for turning said turret, substantially as described.

6. The combination,with the chuck and the mechanism for opening and closing the chuckjaws to permit the rod or long stock to be fed forward, of the longitudinal slide, the cam and connections for reciprocating the same, the tool-holding turret mounted on a horizontal axis on said slide, and the mechanism for turning the turret step by step, substantially as described.

7. n a chuck, the combination, with the chuck-jaws, of the cam and connections for closing said jaws by a positive movement by means of a screw, substantially as described.

8. The combination, with the chuck-jaws, of the cam and connections for releasing and for closing said jaws both by the positive action of said cam, substantially as described.

IOO

. substantially as described.

9. YThe combination, with the chuck-jaws,

of the cam, the rigid metal pieces, and the interposed spring for operating the chuck-jaws, the pressure in closing the jaws being communicated through said spring, substantially as described.

' 10. The combination, with the chuck-jaws and mechanism for opening and closing the same, of the adjusting devices at the inner end of the chuck-spindle for regulating the bite of the jaws, substantially as described.

11. rIhe combination, with the chuck-spindle and the chuck-jaws, of the feed or chuck cam, the device acted upon by said cam, the tube inside the spindle, the spring interposed between the said device and the said tube, andthe devices actuated by the tube to close said jaws, substantially as described.

12. The combination, with the adjustable wedges secured to the chuck'head, of the chuck-jaws movable longitudinally with respect to said wedges, substantially as described.

13. The combination, with the wedges united to form a ring, of the inclosed chuck-.jaws formed in one piece of metal, said jaws being beveled on the outside at the ends to correspond with the wedges, and being movable by means of a screw with respect to said wedges,

14. In a chuck, the combination, with head, the wedges, and the chuck-jaw, of the screw-follower and the tube connected with f said follower by a pin workingl in an oblique slot, substantially as described.

15. In a chuck, the combination, with the tube for operating the chuck-jaws and the nuts on the outer end of the tube, of the device the Y for communicating motion to said 4tube and the spring interposed between said device and one of said nuts, substantially as described.

16. In a chuck, the combination, with lthe head, the ring therein, the follower connected with said ring by a screw-thread, and the tube connected with said follower by a pin working in an oblique slot, of the notched flange and locking-pin for adjusting the said rlng in said head, substantially as described.

17. The combination of the chuck-head, the wedges, the chuck-jaws, and the screw-follower, substantially as described, so that the jaws are compressed automatically by the combined action of the screw and wedges, as set forth.

18. The combination, in a chuclgwith the chuck-jaws and screw-follower, of the adjustable ring engaging the thread on said follower, substantially as described.

19. In a chuck, the combination, with the head, the ring, the follower connected with said ring by a screw-thread, and the tube so connected with the follower as to revolve the follower by its reciprocating motion, substantially as described.

20. In a chuck, the combination, with the head, the ring therein, and the follower connected with said ring by a screw-thread, substantially as described.

YIn testimony whereof I have signed-this specification in the presence of two subscribing witnesses.

ALLEN JOHNSTON.

Witnesses:

J. T. HAcKwoRTH, A. G. HARRow. 

